173 lines
4.4 KiB
C
173 lines
4.4 KiB
C
/* This file is part of the sample code and exercises
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* used by the class "Advanced Programming in the UNIX
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* Environment" taught by Jan Schaumann
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* <jschauma@netmeister.org> at Stevens Institute of
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* Technology.
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*
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* https://stevens.netmeister.org/631/
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*/
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/* Increasingly loosely based on:
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* $NetBSD: strchkread.c,v 1.3 2003/08/07 10:30:50 agc Exp $
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*
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* Copyright (c) 1986, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)strchkread.c 8.1 (Berkeley) 6/8/93
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*/
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#include <arpa/inet.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <sys/wait.h>
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#include <netinet/in.h>
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#include <netdb.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#define BACKLOG 5
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#ifndef SLEEP
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#define SLEEP 5
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#endif
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int
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createSocket(void)
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{
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int sock;
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socklen_t length;
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struct sockaddr_in6 server;
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memset(&server, 0, sizeof(server));
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if ((sock = socket(PF_INET6, SOCK_STREAM, 0)) < 0) {
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perror("opening stream socket");
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exit(EXIT_FAILURE);
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/* NOTREACHED */
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}
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server.sin6_family = PF_INET6;
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server.sin6_addr = in6addr_any;
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server.sin6_port = 0;
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if (bind(sock, (struct sockaddr *)&server, sizeof(server)) != 0) {
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perror("binding stream socket");
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exit(EXIT_FAILURE);
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/* NOTREACHED */
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}
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length = sizeof(server);
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if (getsockname(sock, (struct sockaddr *)&server, &length) != 0) {
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perror("getting socket name");
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exit(EXIT_FAILURE);
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/* NOTREACHED */
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}
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(void)printf("Socket has port #%d\n", ntohs(server.sin6_port));
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if (listen(sock, BACKLOG) < 0) {
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perror("listening");
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exit(EXIT_FAILURE);
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/* NOTREACHED */
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}
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return sock;
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}
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void
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handleSocket(int s)
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{
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int fd, rval;
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char claddr[INET6_ADDRSTRLEN];
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struct sockaddr_in6 client;
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socklen_t length;
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const char *rip;
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length = sizeof(client);
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memset(&client, 0, length);
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if ((fd = accept(s, (struct sockaddr *)&client, &length)) < 0) {
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perror("accept");
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return;
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}
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if ((rip = inet_ntop(PF_INET6, &(client.sin6_addr), claddr, INET6_ADDRSTRLEN)) == NULL) {
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perror("inet_ntop");
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rip = "unknown";
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} else {
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(void)printf("Client connection from %s!\n", rip);
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}
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do {
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char buf[BUFSIZ];
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bzero(buf, sizeof(buf));
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if ((rval = read(fd, buf, BUFSIZ)) < 0)
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perror("reading stream message");
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else if (rval == 0)
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printf("Ending connection from %s.\n", rip);
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else
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printf("Client (%s) sent: %s", rip, buf);
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} while (rval != 0);
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(void)close(fd);
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}
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/*
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* This program uses select() to check that someone is trying to connect
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* before calling accept().
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*/
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int
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main()
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{
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int s1;
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s1 = createSocket();
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for (;;) {
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fd_set ready;
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struct timeval to;
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FD_ZERO(&ready);
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FD_SET(s1, &ready);
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to.tv_sec = SLEEP;
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to.tv_usec = 0;
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if (select(s1 + 1, &ready, 0, 0, &to) < 0) {
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perror("select");
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continue;
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}
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if (FD_ISSET(s1, &ready)) {
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handleSocket(s1);
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} else {
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(void)printf("Idly sitting here, waiting for connections...\n");
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}
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}
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/* NOTREACHED */
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}
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